1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * List pending timers
4 *
5 * Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
6 */
7
8 #include <linux/proc_fs.h>
9 #include <linux/module.h>
10 #include <linux/spinlock.h>
11 #include <linux/sched.h>
12 #include <linux/seq_file.h>
13 #include <linux/kallsyms.h>
14 #include <linux/nmi.h>
15
16 #include <linux/uaccess.h>
17
18 #include "tick-internal.h"
19
20 struct timer_list_iter {
21 int cpu;
22 bool second_pass;
23 u64 now;
24 };
25
26 /*
27 * This allows printing both to /proc/timer_list and
28 * to the console (on SysRq-Q):
29 */
30 __printf(2, 3)
SEQ_printf(struct seq_file * m,const char * fmt,...)31 static void SEQ_printf(struct seq_file *m, const char *fmt, ...)
32 {
33 va_list args;
34
35 va_start(args, fmt);
36
37 if (m)
38 seq_vprintf(m, fmt, args);
39 else
40 vprintk(fmt, args);
41
42 va_end(args);
43 }
44
45 static void
print_timer(struct seq_file * m,struct hrtimer * taddr,struct hrtimer * timer,int idx,u64 now)46 print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
47 int idx, u64 now)
48 {
49 SEQ_printf(m, " #%d: <%p>, %ps", idx, taddr, ACCESS_PRIVATE(timer, function));
50 SEQ_printf(m, ", S:%02x", timer->state);
51 SEQ_printf(m, "\n");
52 SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
53 (unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
54 (unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
55 (long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
56 (long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
57 }
58
59 static void
print_active_timers(struct seq_file * m,struct hrtimer_clock_base * base,u64 now)60 print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
61 u64 now)
62 {
63 struct hrtimer *timer, tmp;
64 unsigned long next = 0, i;
65 struct timerqueue_node *curr;
66 unsigned long flags;
67
68 next_one:
69 i = 0;
70
71 touch_nmi_watchdog();
72
73 raw_spin_lock_irqsave(&base->cpu_base->lock, flags);
74
75 curr = timerqueue_getnext(&base->active);
76 /*
77 * Crude but we have to do this O(N*N) thing, because
78 * we have to unlock the base when printing:
79 */
80 while (curr && i < next) {
81 curr = timerqueue_iterate_next(curr);
82 i++;
83 }
84
85 if (curr) {
86
87 timer = container_of(curr, struct hrtimer, node);
88 tmp = *timer;
89 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
90
91 print_timer(m, timer, &tmp, i, now);
92 next++;
93 goto next_one;
94 }
95 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
96 }
97
98 static void
print_base(struct seq_file * m,struct hrtimer_clock_base * base,u64 now)99 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
100 {
101 SEQ_printf(m, " .base: %p\n", base);
102 SEQ_printf(m, " .index: %d\n", base->index);
103
104 SEQ_printf(m, " .resolution: %u nsecs\n", hrtimer_resolution);
105 #ifdef CONFIG_HIGH_RES_TIMERS
106 SEQ_printf(m, " .offset: %Lu nsecs\n",
107 (unsigned long long) ktime_to_ns(base->offset));
108 #endif
109 SEQ_printf(m, "active timers:\n");
110 print_active_timers(m, base, now + ktime_to_ns(base->offset));
111 }
112
print_cpu(struct seq_file * m,int cpu,u64 now)113 static void print_cpu(struct seq_file *m, int cpu, u64 now)
114 {
115 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
116 int i;
117
118 SEQ_printf(m, "cpu: %d\n", cpu);
119 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
120 SEQ_printf(m, " clock %d:\n", i);
121 print_base(m, cpu_base->clock_base + i, now);
122 }
123 #define P(x) \
124 SEQ_printf(m, " .%-15s: %Lu\n", #x, \
125 (unsigned long long)(cpu_base->x))
126 #define P_ns(x) \
127 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \
128 (unsigned long long)(ktime_to_ns(cpu_base->x)))
129
130 #ifdef CONFIG_HIGH_RES_TIMERS
131 P_ns(expires_next);
132 P(hres_active);
133 P(nr_events);
134 P(nr_retries);
135 P(nr_hangs);
136 P(max_hang_time);
137 #endif
138 #undef P
139 #undef P_ns
140
141 #ifdef CONFIG_TICK_ONESHOT
142 # define P(x) \
143 SEQ_printf(m, " .%-15s: %Lu\n", #x, \
144 (unsigned long long)(ts->x))
145 # define P_ns(x) \
146 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \
147 (unsigned long long)(ktime_to_ns(ts->x)))
148 # define P_flag(x, f) \
149 SEQ_printf(m, " .%-15s: %d\n", #x, !!(ts->flags & (f)))
150
151 {
152 struct tick_sched *ts = tick_get_tick_sched(cpu);
153 P_flag(nohz, TS_FLAG_NOHZ);
154 P_flag(highres, TS_FLAG_HIGHRES);
155 P_ns(last_tick);
156 P_flag(tick_stopped, TS_FLAG_STOPPED);
157 P(idle_jiffies);
158 P(idle_calls);
159 P(idle_sleeps);
160 P_ns(idle_entrytime);
161 P_ns(idle_waketime);
162 P_ns(idle_exittime);
163 P_ns(idle_sleeptime);
164 P_ns(iowait_sleeptime);
165 P(last_jiffies);
166 P(next_timer);
167 P_ns(idle_expires);
168 SEQ_printf(m, "jiffies: %Lu\n",
169 (unsigned long long)jiffies);
170 }
171 #endif
172
173 #undef P
174 #undef P_ns
175 SEQ_printf(m, "\n");
176 }
177
178 #ifdef CONFIG_GENERIC_CLOCKEVENTS
179 static void
print_tickdevice(struct seq_file * m,struct tick_device * td,int cpu)180 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
181 {
182 struct clock_event_device *dev = td->evtdev;
183
184 touch_nmi_watchdog();
185
186 SEQ_printf(m, "Tick Device: mode: %d\n", td->mode);
187 if (cpu < 0)
188 SEQ_printf(m, "Broadcast device\n");
189 else
190 SEQ_printf(m, "Per CPU device: %d\n", cpu);
191
192 SEQ_printf(m, "Clock Event Device: ");
193 if (!dev) {
194 SEQ_printf(m, "<NULL>\n");
195 return;
196 }
197 SEQ_printf(m, "%s\n", dev->name);
198 SEQ_printf(m, " max_delta_ns: %llu\n",
199 (unsigned long long) dev->max_delta_ns);
200 SEQ_printf(m, " min_delta_ns: %llu\n",
201 (unsigned long long) dev->min_delta_ns);
202 SEQ_printf(m, " mult: %u\n", dev->mult);
203 SEQ_printf(m, " shift: %u\n", dev->shift);
204 SEQ_printf(m, " mode: %d\n", clockevent_get_state(dev));
205 SEQ_printf(m, " next_event: %Ld nsecs\n",
206 (unsigned long long) ktime_to_ns(dev->next_event));
207
208 SEQ_printf(m, " set_next_event: %ps\n", dev->set_next_event);
209
210 if (dev->set_state_shutdown)
211 SEQ_printf(m, " shutdown: %ps\n",
212 dev->set_state_shutdown);
213
214 if (dev->set_state_periodic)
215 SEQ_printf(m, " periodic: %ps\n",
216 dev->set_state_periodic);
217
218 if (dev->set_state_oneshot)
219 SEQ_printf(m, " oneshot: %ps\n",
220 dev->set_state_oneshot);
221
222 if (dev->set_state_oneshot_stopped)
223 SEQ_printf(m, " oneshot stopped: %ps\n",
224 dev->set_state_oneshot_stopped);
225
226 if (dev->tick_resume)
227 SEQ_printf(m, " resume: %ps\n",
228 dev->tick_resume);
229
230 SEQ_printf(m, " event_handler: %ps\n", dev->event_handler);
231 SEQ_printf(m, "\n");
232 SEQ_printf(m, " retries: %lu\n", dev->retries);
233
234 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
235 if (cpu >= 0) {
236 const struct clock_event_device *wd = tick_get_wakeup_device(cpu);
237
238 SEQ_printf(m, "Wakeup Device: %s\n", wd ? wd->name : "<NULL>");
239 }
240 #endif
241 SEQ_printf(m, "\n");
242 }
243
timer_list_show_tickdevices_header(struct seq_file * m)244 static void timer_list_show_tickdevices_header(struct seq_file *m)
245 {
246 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
247 print_tickdevice(m, tick_get_broadcast_device(), -1);
248 SEQ_printf(m, "tick_broadcast_mask: %*pb\n",
249 cpumask_pr_args(tick_get_broadcast_mask()));
250 #ifdef CONFIG_TICK_ONESHOT
251 SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n",
252 cpumask_pr_args(tick_get_broadcast_oneshot_mask()));
253 #endif
254 SEQ_printf(m, "\n");
255 #endif
256 }
257 #endif
258
timer_list_header(struct seq_file * m,u64 now)259 static inline void timer_list_header(struct seq_file *m, u64 now)
260 {
261 SEQ_printf(m, "Timer List Version: v0.10\n");
262 SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
263 SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
264 SEQ_printf(m, "\n");
265 }
266
sysrq_timer_list_show(void)267 void sysrq_timer_list_show(void)
268 {
269 u64 now = ktime_to_ns(ktime_get());
270 int cpu;
271
272 timer_list_header(NULL, now);
273
274 for_each_online_cpu(cpu)
275 print_cpu(NULL, cpu, now);
276
277 #ifdef CONFIG_GENERIC_CLOCKEVENTS
278 timer_list_show_tickdevices_header(NULL);
279 for_each_online_cpu(cpu)
280 print_tickdevice(NULL, tick_get_device(cpu), cpu);
281 #endif
282 return;
283 }
284
285 #ifdef CONFIG_PROC_FS
timer_list_show(struct seq_file * m,void * v)286 static int timer_list_show(struct seq_file *m, void *v)
287 {
288 struct timer_list_iter *iter = v;
289
290 if (iter->cpu == -1 && !iter->second_pass)
291 timer_list_header(m, iter->now);
292 else if (!iter->second_pass)
293 print_cpu(m, iter->cpu, iter->now);
294 #ifdef CONFIG_GENERIC_CLOCKEVENTS
295 else if (iter->cpu == -1 && iter->second_pass)
296 timer_list_show_tickdevices_header(m);
297 else
298 print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu);
299 #endif
300 return 0;
301 }
302
move_iter(struct timer_list_iter * iter,loff_t offset)303 static void *move_iter(struct timer_list_iter *iter, loff_t offset)
304 {
305 for (; offset; offset--) {
306 iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
307 if (iter->cpu >= nr_cpu_ids) {
308 #ifdef CONFIG_GENERIC_CLOCKEVENTS
309 if (!iter->second_pass) {
310 iter->cpu = -1;
311 iter->second_pass = true;
312 } else
313 return NULL;
314 #else
315 return NULL;
316 #endif
317 }
318 }
319 return iter;
320 }
321
timer_list_start(struct seq_file * file,loff_t * offset)322 static void *timer_list_start(struct seq_file *file, loff_t *offset)
323 {
324 struct timer_list_iter *iter = file->private;
325
326 if (!*offset)
327 iter->now = ktime_to_ns(ktime_get());
328 iter->cpu = -1;
329 iter->second_pass = false;
330 return move_iter(iter, *offset);
331 }
332
timer_list_next(struct seq_file * file,void * v,loff_t * offset)333 static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset)
334 {
335 struct timer_list_iter *iter = file->private;
336 ++*offset;
337 return move_iter(iter, 1);
338 }
339
timer_list_stop(struct seq_file * seq,void * v)340 static void timer_list_stop(struct seq_file *seq, void *v)
341 {
342 }
343
344 static const struct seq_operations timer_list_sops = {
345 .start = timer_list_start,
346 .next = timer_list_next,
347 .stop = timer_list_stop,
348 .show = timer_list_show,
349 };
350
init_timer_list_procfs(void)351 static int __init init_timer_list_procfs(void)
352 {
353 struct proc_dir_entry *pe;
354
355 pe = proc_create_seq_private("timer_list", 0400, NULL, &timer_list_sops,
356 sizeof(struct timer_list_iter), NULL);
357 if (!pe)
358 return -ENOMEM;
359 return 0;
360 }
361 __initcall(init_timer_list_procfs);
362 #endif
363